User's Guide ______________________________________________________________________
60 __________________________________________________________________ M210482EN-B
3RD LINE
The second line of the message is a backscatter data line.
Example:
D
1
D
2
D
3
D
4
........................D
64
↵
where
D =
A single, ASCII coded hexadecimal character O ... F, where
each bit of the 4-bit nibble of the hex character expressed in
a binary form represents one range gate.
D
1
=
Represents the four lowest 15 m (approximately 50 ft)
range gates, that is, 45 m (appr. 0 ft, 50 ft, l00 ft, 150 ft).
D
2
=
Represents the four next ones, that is, 60 m (appr. 200 ft,
250 ft, 300 ft, 350 ft), etc.
0
Indicates no detectable backscatter in four adjacent range gates
F
Indicates backscatter in all four range gates
8
Indicates backscatter in the lowest range gate only
1
Indicates backscatter in the highest range gate only
All other characters indicate a gate-by-gate combination of backscatter
according to the binary nibble, converted to hexadecimal.
CT25K Data Messages
Ceilometer CL31 also includes two Ceilometer CT25K data messages.
These are data message No. 1 and data message No. 6.
CT25K Data Message No. 1
This message is intended for cloud height/vertical visibility
measurement when no other measurement information is desired. The
message includes the most elementary status information, which
enables a host system or operator to see that no warnings or alarms are
present. An example of data message No.1 is presented below:
CTA2010
☺
↵
1st line
11 char.
30 01230 12340 23450 FEDCBA98
↵
2nd line
31 char.
↵
3rd line
3 char.
------------------
total 44 characters
